Position-based performance of a vehicle function in a vehicle communication system

ABSTRACT

A vehicle communication system ( 100 ) for facilitating control over a function of a vehicle ( 102 ) comprises a base station ( 104 ) positioned in the vehicle ( 102 ) and a mobile communication unit ( 122 ). The base station ( 104 ) comprises a first transmitter for transmitting a signal to the mobile communication unit and a first receiver for receiving a signal from the mobile communication unit ( 122 ). The base station ( 104 ) is configured to receive a first request from the mobile communication unit ( 122 ), wherein the first request seeks performance of a first vehicle function, determine a position of the mobile communication unit ( 122 ) relative to the vehicle ( 102 ), compare the position of the mobile communication unit ( 122 ) relative to the vehicle ( 102 ) to a first criteria, and facilitate performance of the first vehicle function if the position of the mobile communication unit ( 122 ) relative to the vehicle ( 102 ) satisfies the first criteria.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/894,527, filed Nov. 29, 2015, which itself is a 35 U.S.C. §371national stage application of PCT Application No. PCT/EP2014/061210,filed on May 29, 2014, which claims priority from Great Britain PatentApplication No. 1309744.9, filed on May 31, 2013, the contents of whichare incorporated herein by reference in their entireties. Theabove-referenced PCT International Application was published in theEnglish language as International Publication No. WO 2014/191537 A1 onDec. 4, 2014.

TECHNICAL FIELD

The present invention relates to a vehicle communication system forfacilitating control over vehicle functions. The present inventionrelates more particularly, but not exclusively, to systems and methodsfor facilitating control over vehicle functions based, at least in part,on position of a mobile communication unit. Aspects of the inventionrelate to a system, to a method and to a vehicle.

BACKGROUND OF THE INVENTION

In today's world, many vehicles are equipped with systems forfacilitating remotely controlled vehicle functions such as passive entryand passive starting (i.e., PEPS) of a host vehicle. When a vehicle isequipped with a PEPS system, a user may carry a mobile communicationunit which can communicate with a base station located in the vehicle.To initiate communication, the base station may emit a relativelypowerful Low Frequency (LF) electromagnetic field, causing a mobilecommunication unit that is sufficiently close to the base station toawaken. Once the mobile communication unit is awake, it may use RadioFrequency (RF) transmissions to dispatch signals, which may be validatedby the base station. If the base station recognizes and approves theidentity of the mobile communication unit, (i.e., the base stationauthenticates the mobile communication unit), the base station mayfacilitate the performance of a predefined vehicle function, such asactuating a door lock mechanism, causing the door to become unlocked. Insuch passive systems, the functions may be performed based solely on theposition, or changes in the position, of the mobile communication unit,and the functions may be performed even though no specific command mayhave been initiated by the user.

For example, in some passive systems, an approach of the mobilecommunication unit toward the vehicle may be detected so that a desirefor one or more vehicle functions to be performed (e.g., unlockingdoors) may be anticipated and automatically provided in a manner thatenhances the operator experience. In other passive systems, a departureof the mobile communication unit away from the vehicle may be detectedso that one or more other functions (e.g., locking vehicle doors) may beperformed.

In addition to the above-described passive communications, a vehiclecommunication system may also be configured to facilitate activecommunications among system components. Active communications mayinclude transmissions initiated by a user seeking performance of apre-defined function. For example, a user, by pressing a button oractuating a switch on a mobile communication unit, may actively initiateactive communications with the vehicle, sending a command to lock orunlock the vehicle doors or to actively start the vehicle engine.

Unfortunately, by facilitating such active interactions, a vehiclecommunication system may increase the possibility for a user to submitan unintentional or inadvertent communication input via the mobilecommunication unit. If the user is in a position to observe theinadvertent instruction being performed, the user may correct the errorby issuing a counteracting request. If the user is not so advantageouslypositioned, however, no corrective action may be initiated, and anundesirable consequence may occur. For example, if a mobilecommunication unit were configured with a button for sounding an alarmon the vehicle, and if a user were to inadvertently press the buttonwhile being situated so as to be unable to hear the alarm, yet withinrange for the command to be received by a base station in the vehicle,the alarm may be unintentionally activated without the knowledge of theuser.

While such events are annoying, they may not be nearly as wasteful ashaving the vehicle engine running all day long while the userunknowingly conducts a full day of affairs in a nearby office. One canenvision more damaging consequences where the mobile communication unitis configured for enabling a user to remotely open the vehicle windows.Thus, it would be advantageous to have a vehicle communication systemthat provides for active communications with a vehicle and control overvehicle functions, while also decreasing the likelihood of dispatchinginadvertent or unintentional commands to be performed by the vehicle.

The present invention attempts to address or ameliorate at least some ofthe above problems associated with vehicle communication systems.

SUMMARY OF THE INVENTION

In one aspect, the present invention provides a vehicle communicationsystem for facilitating control over a function of a vehicle comprisinga base station positioned in the vehicle and a mobile communicationunit. The base station comprises a first transmitter for transmitting asignal to the mobile communication unit and, a first receiver forreceiving a signal from the mobile communication unit. The base stationis configured to receive a first request from the mobile communicationunit, wherein the first request seeks performance of a first vehiclefunction. The base station is also configured to determine a position ofthe mobile communication unit relative to the vehicle and to compare theposition of the mobile communication unit relative to the vehicle to afirst criteria. Finally, the base station is configured to facilitateperformance of the first vehicle function if the position of the mobilecommunication unit relative to the vehicle satisfies the first criteria.

The base station may be configured to determine the position of themobile communication unit relative to the vehicle based on a time offlight method. The first transmitter may be an ultra-widebandtransmitter and the first receiver may be an ultra-wideband receiver. Itis a particular advantage of ultra-wide communications that it ispossible to distinguish between signals which travel along a direct pathbetween transmitter and receiver and those which follow non-directpaths. Accordingly, this allows the position of the mobile communicationunit relative to the vehicle to be established with a high degree ofaccuracy, much more so than distance measurements in conventionalnarrow-band systems which typically rely on radio signal strengthintensity (RSSI) measurements.

The base station may be configured to facilitate performance of thefirst vehicle function only if the position of the mobile communicationunit satisfies the first criteria. In one embodiment, the firstcriterion requires that the position be less than a first distance fromthe vehicle. In another alternative embodiment, the first criterionrequires that the position be greater than a first distance from thevehicle.

In another embodiment, the base station is configured to receive asecond request from the mobile communication unit, wherein the secondrequest seeks performance of a second vehicle function. In thisembodiment, the base station is configured to compare the position ofthe mobile communication unit relative to the vehicle to a secondcriteria and to facilitate performance of the second vehicle function ifthe position of the mobile communication unit relative to the vehiclesatisfies the second criteria. The base station may be configured tofacilitate performance of the first vehicle function only if theposition of the mobile communication unit satisfies the first criteria,and may also be configured to facilitate performance of the secondvehicle function only if the position of the mobile communication unitsatisfies the second criteria. The first criterion may require that theposition be within a first distance from the vehicle, and the secondcriterion may require that the position be within a second distance fromthe vehicle. The first distance may be greater than the second distance.

In another embodiment, a vehicle communication system includes a basestation that is configured to receive a third request from the mobilecommunication unit, the third request seeking performance of a thirdvehicle function. In this embodiment, the base station is configured tocompare the position of the mobile communication unit relative to thevehicle to a third criterion and facilitate performance of the thirdvehicle function if the position of the mobile communication unitrelative to the vehicle satisfies the third criteria.

In an embodiment, the base station is configured to facilitateperformance of the first vehicle function only if the position of themobile communication unit satisfies the first criteria, to facilitateperformance of the second vehicle function only if the position of themobile communication unit satisfies the second criteria, and tofacilitate performance of the third vehicle function only if theposition of the mobile communication unit satisfies the third criteria.The first criteria may require that the position be within a firstdistance from the vehicle, the second criteria may require that theposition be within a second distance from the vehicle, and the thirdcriteria may require that the position be within a third distance fromthe vehicle. The first distance may be greater than the second distance,and the second distance may be greater than the third distance.

In an embodiment, the first vehicle function comprises locking anaperture of the vehicle, the second vehicle function comprises startingan engine of the vehicle, and the third vehicle function comprisesopening an aperture of the vehicle. The third vehicle function may alsocomprise closing an aperture of the vehicle.

In another aspect, a method for facilitating control over a function ofa vehicle comprises providing a base station positioned in the vehicleand a mobile communication unit, wherein the base station comprises afirst transmitter for transmitting a signal and a first receiver forreceiving a signal from the mobile communication unit. The method alsoincludes receiving a first request from the mobile communication unit,wherein the first request seeks performance of a first vehicle function,and determining a position of the mobile communication unit relative tothe vehicle. Finally, the method includes comparing the position of themobile communication unit relative to the vehicle to a predeterminedfirst criteria and facilitating performance of the first request if theposition of the mobile communication unit relative to the vehiclesatisfies a first criteria.

Determining the position of the mobile communication unit relative tothe vehicle may be based on a time of flight method. The firsttransmitter may be an ultra-wideband transmitter and the first receivermay be an ultra-wideband receiver.

In another embodiment, a method for facilitating control over a functionof a vehicle further comprises receiving a second request from themobile communication unit, wherein the second request seeks performanceof a second vehicle function. Still further, the method comprisescomparing the position of the mobile communication unit relative to thevehicle to a second criteria and facilitating performance of the secondvehicle function if the position of the mobile communication unitrelative to the vehicle satisfies the second criteria.

In a further embodiment, a method for facilitating control over afunction of a vehicle also includes receiving a third request from themobile communication unit, wherein the third request seeks performanceof a third vehicle function_(—) The position of the mobile communicationunit relative to the vehicle is compared to a third criterion, andperformance of the third vehicle function is facilitated if the positionof the mobile communication unit relative to the vehicle satisfies thethird criteria.

In another aspect of the invention, a vehicle may be provided having avehicle communication system, or being adapted to perform a method, asdescribed in the preceding paragraphs of this section.

Within the scope of this application it is expressly intended that thevarious aspects, embodiments, examples and alternatives set out in thepreceding paragraphs, in the claims and/or in the following descriptionand drawings, and in particular the individual features thereof, may betaken independently or in any combination. For example, featuresdescribed in connection with one embodiment are applicable to allembodiments unless such features are incompatible.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the present invention will now be described,by way of example only, with reference to the accompanying figures, inwhich:

FIG. 1 shows a schematic representation of a vehicle communicationsystem according to an embodiment of the present invention;

FIG. 2 shows the installation of the base station and transceivers ofthe vehicle communication system according to one embodiment of thepresent invention in a motor vehicle;

FIG. 3 shows an operating mode of the vehicle communication systemaccording to one embodiment of the present invention;

FIG. 4 illustrates another operating mode of the vehicle communicationsystem according to one embodiment of the present invention;

FIG. 5 illustrates another operating mode of the vehicle communicationsystem according to one embodiment of the present invention; and

FIG. 6 illustrates another operating mode of the vehicle communicationsystem according to one embodiment of the present invention.

DETAILED DESCRIPTION

FIG. 1 shows a vehicle communication system 100 in accordance with anembodiment of the present invention. The vehicle communication system100 is configured to facilitate transfer of information among componentsof the vehicle communication system 100, which may further facilitatecontrol over one or more functions of a vehicle 102. Exemplary functionsthat may be controlled include, but are not limited to, enhanced PassiveEntry and Passive Start (ePEPS) keyless access, remote engine start,remote opening and closing of vehicle apertures, deployment andretraction of external mirrors or antennas, and/or activation anddeactivation of lighting and signalling systems of the vehicle 102.

The vehicle communication system 100 will be described with reference tothe vehicle 102 which has a front right door 142, a rear right door 144,a front left door 146 and a rear left door 148. The vehicle 102 also hasa boot lid 150 (also known as a deck lid) which can be locked/unlockedby the vehicle communication system 100 but this is not described hereinfor the sake of brevity. The doors 142-148 each have a lock mechanismand an external handle; and the front doors 142, 146 each have a foldingdoor mirror. The lock mechanisms each comprise a door lock switch toprovide a locking signal to indicate the status of the respective lockmechanism.

The vehicle communication system 100 comprises a base station 104 to beinstalled in the vehicle 102 to provide a Remote Function Actuator (RFA)for the vehicle 102. The base station 104 comprises an electroniccontrol unit 106 and a first rechargeable battery 108. The electroniccontrol unit 106 comprises a memory storage device 107 that is incommunication with one or more processor(s) 109. The processor(s) 109can be configured to perform computational operations in accordance withinstructions (e.g., software) stored in the memory storage device 107.The first rechargeable battery 108 provides a dedicated power supply forthe base station 104 to enable its operation independently from avehicle power system (not shown).

The base station 104 further comprises first, second and thirdultra-wideband transceivers 110, 112, 114. The first transceiver 110 isprovided proximal the electronic control unit 106. The second and thirdtransceivers 112, 114 are positioned in the vehicle 102 remote from theelectronic control unit 106 and connected via a dedicated localinterconnect network (LIN) 116. The transceivers 110, 112, 114 each havean integrated antenna. As discussed more fully below, the vehiclecommunication system 100 may further comprise a fourth transceiver (notshown) which is also positioned in the vehicle 102 remote from theelectronic control unit 106 and connected via the dedicated localinterconnect network (LIN) 116.

The base station 104 is connected to the vehicle systems (denotedgenerally by the reference numeral 118) via a CAN bus 120. The basestation 104 can thereby receive signals from the vehicle systems (e.g.,locking signals from door lock switches); and can control operation ofone or more vehicle systems (e.g., door lock mechanisms, closure systemsfor vehicle apertures such as windows, sun roof, ventilation systems,deck lid, engine start/ignition, vehicle lighting, entertainmentsystems, horn, heater, air conditioning, and the like). The CAN bus 120can also be employed to convey instructions from the electronic controlunit 106 to other systems (e.g., actuators, controls) of the vehicle102, such as the engine control unit, to facilitate enabling and/ordisabling of one or more vehicle systems (e.g., passive enginestarting).

The vehicle communication system 100 further comprises a mobilecommunication unit 122 having a remote ultra-wideband transceiver 124and a second rechargeable battery 126. The mobile communication unit 122is portable to facilitate its being carried by the user. As describedherein, the mobile communication unit 122 communicates with the basestation 104 to facilitate control over vehicle functions, such aspassive entry to the vehicle 102, and, under some circumstances, toprovide information to a user in possession of the mobile communicationunit 122.

The base station 104 further comprises a dock 128 for receiving themobile communication unit 122. The dock 128 has a port 130 to enablecommunication between the base station 104 and the mobile communicationunit 122. A charging pad 132 is also provided in the dock 128 tofacilitate charging of the second rechargeable battery 126 when themobile communication unit 122 is docked and thus mated with the chargingpad 132. A bi-colour light emitting diode 134 is provided in the dock128 to indicate the status of the mobile communication unit 122 (forexample to indicate that the second rechargeable battery 126 is chargingor is fully charged). The charging pad 132 is connected to a powersupply unit (PSU) provided in the base station 104. An external chargeport 136 for the base station 104 is provided for charging the firstrechargeable battery 108.

The installation of the vehicle communication system 100 is illustratedin FIG. 2. The base station 104 and the first transceiver 110 arelocated at the rear of the vehicle 102 and the second and thirdtransceivers 112, 114 are located in the upper part of the vehicle 102(typically in the roof) on the right and left sides respectively of thevehicle 102. As illustrated by dashed lines in FIG. 2, the transceivers110, 112, 114 communicate with the mobile communication unit 122. Thedistance from each of the first, second and third transceivers 110, 112,114 to the remote transceiver 124 can be determined by measuringtransmission and/or response time (for example, time of flight for asignal transmission) thereby allowing the position of the mobilecommunication unit 122 in relation to the vehicle 102 to be determinedthrough triangulation. The use of ultra-wideband frequencies (typicallygreater than 3 GHz) allows the position of the mobile communication unit122 to be tracked with a relatively high degree of accuracy.

In accordance with such an embodiment of the vehicle communicationsystem 100, wherein the base station 104 comprises three transceivers110, 112, 114 disposed at spaced-apart positions within the vehicle 102,it is possible to use the transmission and/or response times forcommunications sent between the mobile communication unit 122 and eachof the transceivers 110, 112, 114 to determine a position of the mobilecommunication unit 122 relative to the vehicle 102 along each of twoaxes. For example, with the base station 104 and the first transceiver110 located toward the rear of the vehicle 102 and with the second andthird transceivers 112, 114 disposed within the roof (on respective leftand right sides), the position of the mobile communication unit 122relative to the vehicle 102 can readily be determined, i.e. as shown inthe plan view of FIGS. 2 to 6.

However, with the second and third transceivers 112, 114 disposed in thevehicle roof, and therefore lying in the same horizontal plane, theremay be situations in which it is not possible to readily determine theposition of the mobile communication unit 122 along a direction normalto the plan views of FIGS. 2 to 6 (i.e., above or below the vehicle102). Accordingly, in a further embodiment of the invention, the vehiclecommunication system 100 may comprise a fourth transceiver (not shown)which is disposed within the vehicle 102 at a position that is spacedapart in a vertical direction from both the plane of the vehicle roofand the horizontal plane in which the base station 104 lies. Forexample, the fourth transceiver (not shown) could be mounted in thevehicle dashboard on the vehicle center line. With this configuration,the height of the mobile communication unit 122 relative to the vehicle102 can readily be determined.

Thus, a position of the mobile communication unit 122 relative to thevehicle 102 may be periodically or continuously determined and may besaved in the memory storage device 107 for subsequent retrieval andanalyses by the processor 109 in accordance with instructions that arealso stored in the memory storage device 107 or pre-programmed into theprocessor 109. Such monitoring and storing and processing of positioninformation may be useful for observing, tracking, and identifying notonly positions of the mobile communication unit 122, but also certainrates, patterns, and/or characteristics of changes in those positions(i.e., movements of the mobile communication unit 122). Accordingly, thevehicle communication system 100 may be configured to detect an approachof the mobile communication unit 122 toward an authorization zone 138defined relatively to the vehicle 102, to detect a departure of themobile communication unit 122 from the authorization zone 138, to detecta continuing presence of the mobile communication unit 122 within theauthorization zone 138, and to recognize patterns involving combinationsof approaches, departures, and prolonged presences relative to theauthorization zone 138 of the vehicle 102. In addition, the vehiclecommunication system 100 may be configured to determine a position ofthe mobile communication unit 122 relative to the vehicle 102 and tocompare that relative position to one or more predetermined (or learned)criteria. The results of that comparison may then be used by the vehiclecommunication system 100 in determining whether and how to transmitfurther communications or to facilitate performance of certain vehiclefunctions.

The remote transceiver 124 of the mobile communication unit 122transmits a polling signal which, when received by the first transceiver110 of the base station 104, initiates communication between the basestation 104 and the mobile communication unit 122. In one embodiment,upon receipt of the polling signal, the first transceiver 110 respondsby transmitting a challenge signal. The challenge signal is received bythe mobile communication unit 122 and prompts the mobile communicationunit 122 to transmit a response signal. The electronic control unit 106receives the response signal and attempts to determine whether it wassent by an authorized device (i.e., to validate or authenticate themobile communication unit 122).

If the response signal is authenticated, the electronic control unit 106continues to communicate with the mobile communication unit 122 andtracks its position in relation to the vehicle 102 and may store theposition information in the memory storage device 107 for retrieval andprocessing by the processor 109 in accordance with pre-definedinstructions. Moreover, provided the challenge/response sequence iscompleted successfully, the electronic control unit 106 will providecontrol over functions of the vehicle 102 subject to satisfaction ofoperating criteria. If the response signal is not authenticated, theelectronic control unit 106 will not facilitate user control overvehicle functions, such as unlocking the doors of vehicle 102 orstarting the engine of vehicle 102.

In one mode of operation, the polling signal is transmitted continuallyby the remote transceiver 124 so that communication with the basestation 104 is initiated by the mobile communication unit 122.Accordingly, the vehicle communication system 100 can initiate achallenge/response cycle without the need for user interaction, such asactuating a door handle.

In another mode of operation, such as may be active upon first entry ofthe vehicle 102 into service, to conserve energy stored in the secondrechargeable battery 126, the polling signal is transmitted for anoperating period of thirty (30) days. The transmission of the pollingsignal is stopped if the mobile communication unit 122 does notestablish communication with the base station 104 during the operatingperiod. A button provided on the mobile communication unit 122 can bepressed to re-commence transmission of the polling signal after saidoperating period has expired.

In another embodiment, the polling signal is transmitted intermittently,rather than continuously. In accordance with this embodiment, thepolling signal is repeated during the operating period with a timeinterval between transmission cycles (pulses), i.e. the polling signalis transmitted periodically during the operating period. The timeinterval between the transmission cycles can be modified in response tomeasured parameters. For example, the time interval betweentransmissions can be modified depending on the measured distance betweenthe vehicle 102 and the mobile communication unit 122. For example, ifthe mobile communication unit 122 is close to the vehicle 102, the timeinterval can be reduced to one (1) second. Conversely, if the mobilecommunication unit 122 is relatively far away from the vehicle 102, thetime interval can be increased to five (5) seconds.

The base station 104 and the mobile communication unit 122 cancommunicate with each other over a range of at least 20 metres. Theauthorization zone 138 is defined within the communication range. Forexample, the authorization zone 138 may be defined as having a radius of2 metres around the vehicle 102. When the electronic control unit 106determines that the mobile communication unit 122 is inside theauthorization zone 138, the base station 104 may facilitate automaticunlocking of one or more of the vehicle's doors 142-148. Conversely,when the electronic control unit 106 determines that the mobilecommunication unit 122 is outside the authorization zone 138, the basestation 104 may cause the automatic locking of the vehicle's doors142-148.

As discussed above, a vehicle communication system 100 comprising threeor fewer transceivers may be able to determine a position of the mobilecommunication unit 122 relative to the vehicle 102 along only two axes.Accordingly, the authorization zone 138 may be defined in terms of onlythose two axes. A vehicle communication system 100 comprising four ormore transceivers, however, may be able to determine a position of themobile communication unit 122 relative to the vehicle 102 along anycombination of three (optionally orthogonal) axes. Accordingly, thedimensions of the authorization zone 138 may be defined in termspositions along each of the three axes, such that the authorization zone138 (and thus the set of positions that are outside the authorizationzone 138) may be defined in terms of three-dimensional space relative tothe vehicle 102.

Being able to accurately determine the position of the mobilecommunication unit 122 in a three-dimension space around the vehicle 102may be particularly useful in certain situations, for example when thevehicle 102 is parked in a multi-level or multi-story car park oradjacent to a multi-story building. In such situations it is possiblethat the driver, having exited the vehicle 102 may move to another levelof the car park or building above or below the vehicle 102, but maystill be sufficiently close to the vehicle 102 to be within theauthorization zone 138, resulting in one or more of the vehicle doorsbeing automatically unlocked.

Accordingly, if it is determined that the mobile communication unit 122is disposed sufficiently above or below the vehicle 102, such as in theexample of the multi-level car park, the electronic control unit 106 mayuse that position information, if it is known, to not unlock the vehicledoors even when the mobile communication unit 122 would otherwise bejudged to be within an authorization zone 138 defined in only twodimensions.

The electronic control unit 106 may be configured to operate the vehiclecommunication system 100 according to a number of operating modes. In anumber of scenarios, the mobile communication unit 122 is carried on theperson of the user and therefore follows the movements of the user. Inthe accompanying figures, movement paths of the user, and therefore, themobile communication unit 122, are illustrated by a set of footprints140. The process performed by the base station 104 for authenticatingthe mobile communication unit 122 is the same as described above and iscommon to each of the operating modes.

In particular, the remote transceiver 124 transmits a polling signalwhich initiates an authentication cycle with the first transceiver 110.The base station 104 transmits a challenge signal which triggerstransmission of a response signal from the mobile communication unit122. The electronic control unit 106 validates the response signal and,if successful, the base station 104 tracks the range and position of theauthenticated mobile communication unit 122. If the authentication cycleis not successfully completed, for example due to an incorrect responsesignal being sent from the mobile communication unit 122, the functionwill not be performed (e.g., the doors 142-148 will not be unlocked),and the vehicle 102 will not respond to commands dispatched from themobile communication unit 122.

The electronic control unit 106 may be configured to operate the vehiclecommunication system 100 according to a first operating mode asillustrated in FIG. 3. In this operating mode, the vehicle communicationsystem 100 operates to unlock the doors 142-148 on the side of thevehicle 102 on which the user approaches with the mobile communicationunit 122. Having authenticated the mobile communication unit 122, thebase station 104 tracks the range and position of the mobilecommunication unit 122. In the illustrated example, the electroniccontrol unit 106 determines that the mobile communication unit 122 is onthe right hand side of the vehicle 102. Once the base station 104determines that the mobile communication unit 122 is within theauthorization zone 138, the electronic control unit 106 automaticallygenerates a door unlock signal to unlock both doors 142, 144 on theright hand side of the vehicle 102. The door unlock signal istransmitted via the CAN bus 120, and the front right door 142 and therear right door 144 are both unlocked when the mobile communication unit122 enters the authorization zone 138. As the doors 142, 144 areunlocked before the user operates the respective door handle, in normaloperating conditions it is envisaged that there would be no perceptibledelay when the user operates the door handle.

In this mode, when the user operates the door handle on either the frontright door 142 or the rear right door 144, either a single-point entry(SPE) or a multiple-point entry (MPE) can be initiated. In single-pointentry mode, when the drivers door is the only opened door and the keyfob is taken into the vehicle, the rear door on the approached side willbe re-locked. For the avoidance of doubt, the driver's door does nothave to be closed to effect the locking of the rear door. If ANY doorother than driver's door is opened, then all doors will be unlocked andremain so. The action of locking the rear door on the driver's side iscaused by the key fob being detected inside the vehicle and thus nolonger seen in the authorisation zone on the outside of the vehicle. Ina multiple-point entry, the electronic control unit 106 generatescontrol signals to unlock all of the other doors in the vehicle 102 whenthe door handle of either the front right door 142 or the rear rightdoor 144 is operated. It will be appreciated that the front left door146 and the rear left door 148 will be unlocked if base station 104determines that the mobile communication unit 122 enters theauthorization zone 138 on the left hand side of the vehicle 102. Onlywhen the door handle of one of the unlocked doors 142-148 is operated isan indication provided that the doors have been unlocked, for example byflashing the side repeaters and/or extending the door mirrors. If noneof the door handles are operated, however, no indication is providedthat one or more of the doors 142-148 have been unlocked.

The electronic control unit 106 may be configured to operate the vehiclecommunication system 100 according to a second operating mode asillustrated in FIG. 4 to accommodate a walk-past scenario. In thiswalk-past scenario, the user enters and exits the authorization zone 138but does not operate a door handle. As in the first mode describedabove, the base station 104 authenticates the mobile communication unit122 as it approaches the vehicle 102. In this case, the base station 104tracks the position of the mobile communication unit 122 and determinesthat the user is approaching from the rear of the vehicle 102 on theright hand side. As described above in regard to the first mode ofoperation, when the vehicle communication system 100 detects that themobile communication unit 122 has entered the authorization zone 138, asit has in this walk-past scenario, a door unlock signal is transmittedto unlock the front right door 142 and the rear right door 144.

In this scenario, however, the user does not operate the door handle oneither of the doors 142, 144 and, instead, walks past the vehicle 102.Since the vehicle communication system 100 is tracking the position ofthe mobile communication unit 122, the vehicle communication system 100is able to determine when the mobile communication unit 122 leaves theauthorization zone 138. Accordingly, upon the departure of the mobilecommunication unit 122 from the authorization zone 138, and lacking thereceipt of any indication that a door handle has been operated, the basestation 104 transmits a door lock signal to lock the front right door142 and the rear right hand door 144 or otherwise facilitates there-locking of those doors. In one embodiment, the vehicle 102 does notprovide a visual indication when the doors 142, 144 are unlocked orsubsequently locked.

The electronic control unit 106 may be configured to operate the vehiclecommunication system 100 according to a third operating mode asillustrated in FIG. 5 to facilitate the automatic locking of the doors142-148 when the user walks away from the vehicle 102. In this scenario,the user exits the vehicle 102 carrying the mobile communication unit122 and closes the vehicle doors 142-148. In the illustrated example,the user exits the vehicle 102 through the front right door 142 and thencloses it. The user then walks away from the vehicle 102 carrying themobile communication unit 122.

As the mobile communication unit 122 is carried away from the vehicle102, the vehicle communication system 100 tracks the position of themobile communication unit 122 and compares that position to thedefinition of the authorization zone 138. If and when the vehiclecommunication system 100 determines that the mobile communication unit122 has left the authorization zone 138, the vehicle communicationsystem 100 transmits a door lock signal to lock the doors 142-148. Thevehicle 102 is thereby secured automatically without the user activatingthe mobile communication unit 122 or taking any action other thanwalking away from the vehicle 102. A security protocol to comply withindustry standards, for example those specified by Thatcham®, wouldtypically be undertaken for the automatic locking of the doors 142-148.Under normal operating conditions, the automatic locking of the vehicle102 does not double-lock the vehicle 102. Rather, the vehicle 102 wouldonly be double-locked if the user specifically selected this lockingmode, for example via a control panel in the vehicle 102.

The electronic control unit 106 may be further configured to operate thevehicle communication system 100 according to a fourth operating mode asillustrated in FIG. 6 to accommodate a mis-lock scenario. This mode issimilar to the third operating mode described above insofar as the userexits the vehicle 102 through the front right door 142 and closes thedoor 142 before walking away from the vehicle 102. In connection withthis fourth operating mode, the vehicle communication system 100 againdetermines if and when the mobile communication unit 122 has departedthe authorization zone 138. As illustrated in FIG. 6, however, the rearleft door 148 is ajar, and the electronic control unit 106 determinesthat the door 148 cannot be locked (a so-called mis-lock).

To avoid the user leaving the vehicle 102 in an unsecure state (as mayotherwise occur if the operator had not noticed that the rear left door148 was ajar) the electronic control unit 106 transmits an alert signalto the CAN bus 120 and a notification is provided to the user. Forexample, the CAN bus 120 may illuminate the side repeaters and/orprovide an audible warning to notify the user that the doors 142-148have not all been locked. When the rear left door 148 is closed, thevehicle communication system 100 will lock the door 148 to secure thevehicle 102.

In conjunction with the above-described modes of operation, theelectronic control unit 106 may be configured to operate the vehiclecommunication system 100 according to a fifth operating mode,facilitating active communication among components of the vehiclecommunication system 100 while also decreasing the likelihood offacilitating performance of a vehicle function in accordance with aninadvertent or unintentional command. In order to identify and avoidunintended and unnecessary actuation of vehicle systems, it may beadvantageous for the electronic control unit 106 to be able to evaluatewhether a command received from the mobile communication unit 122 is tobe considered reliable, and therefore acted upon.

In many cases, the reliability of a command may be evaluated based onposition or movement information associated with the mobilecommunication unit 122. In other cases, it is acknowledged thatreliability may not be ascertained, and an assessment may nonetheless bemade regarding the gravity of harm that may ensue if an inadvertentcommand were to be carried out. Where an error might be easily detectedand remedial action easily accomplished with little chance for negativeconsequences, the requested action might be performed with a lesserdegree of scrituny. Where the gravity of harm is more severe or thelikelihood of detection less sure or the production of an acceptableremedy more difficult or costly, a greater degree of scrutiny might berequired before performing the requested action.

Thus, in one such embodiment, a vehicle communication system 100 forfacilitating control over a function of a vehicle 102 comprises a basestation 104 that is configured to determine a position of the mobilecommunication unit 122 relative to the vehicle 102 whenever a userinitiated interaction with the vehicle 102 occurs. The position may bestored in the memory for subsequent retrieval and processing. The basestation 104 is configured to evaluate whether the position informationsatisfies predetermined criteria associated with the type of commandthat is received. For example, when a user initiates interaction withthe vehicle 102 including a request to perform a function such asopening a window of the vehicle 102, the base station 104 is configuredto receive the request from the mobile communication unit 122, todetermine a position of the mobile communication unit 122 relative tothe vehicle 102 and to evaluate whether the position informationsatisfies predetermined criteria for requests to open a window oranother aperture of the vehicle 102 (e.g., to compare the position ofthe mobile communication unit 122 relative to the vehicle 102 to thecorresponding criteria).

In one embodiment, the predetermined criteria associated with a requestto open a window or other aperture requires that such commands beperformed only when the mobile communication unit 122 is within a rangeof 25 meters from the vehicle 102. Alternatively, the criterion may callfor the function to be performed only when the mobile communication unit122 is within five or ten meters. If the position of the mobilecommunication unit 122 relative to the vehicle 102 satisfies theappropriate criteria, then the base station 104 facilitates performanceof the requested vehicle function. In one embodiment, the base station104 is configured to facilitate performance of the first vehiclefunction only if the position of the mobile communication unit 122satisfies the first criteria.

A criterion associated with a request for performance of a particularfunction may include that the position of the mobile communication unit122 be less than a predetermined distance from the vehicle 102.Alternatively, a criterion associated with a request for performance ofa particular function may include that the position of the mobilecommunication unit 122 be greater than a predetermined distance from thevehicle 102.

In one embodiment, the base station 104 is configured to receive aplurality of requests (e.g., two requests, three requests, fourrequests, or even ten or more requests) from the mobile communicationunit 122, each request seeking performance of a unique vehicle function.For example, requests may relate to locking or unlocking an aperture ofthe vehicle 102, starting or stopping an engine of the vehicle 102,opening or closing an aperture of the vehicle 102, controlling variousaspects of an environmental control system (e.g., a heater, blower,defroster, air conditioner), controlling various aspects of aninfotainment system (e.g., volume, input source, track, channel, etc.),controlling a vehicle lighting system (e.g., headlamps, fog lamps,interior lighting, puddle lamps), or retrieving information from thevehicle 102 (e.g., a status check).

User controls on the mobile communication unit 122 may be embodied aspushbuttons, touch-screens, switches, dials, knobs, levers, or otherinterfaces known in the art. Each particular request may be associatedwith a unique criterion that must be satisfied before the request isperformed. Alternatively, requests may be classified into a plurality ofcategories, each having one or more prerequisite criteria that must besatisfied. As such, one set of positions for the mobile communicationunit 122 may be acceptable for a first set of requests, while a second,different set of positions for the mobile communication unit 122 may berequired for a second set of requests, and a yet another, third set ofpositions for the mobile communication unit 122 may be required for athird set of requests.

Thus, the base station 104 may be configured to facilitate performanceof a first vehicle function only if the position of the mobilecommunication unit 122 satisfies a first criteria, while also beingconfigured to facilitate performance of a second vehicle function onlyif the position of the mobile communication unit 122 satisfies a secondcriteria, and while further being configured to facilitate performanceof a third vehicle function only if the position of the mobilecommunication unit 122 satisfies a third criteria. To accommodatediffering risks and consequences and remedies associated inadvertentcommands or differing classes, the position criteria may differ from onerequested function to the next.

Similarly to the systems described immediately above, a method forfacilitating control over a function of a vehicle 102 may include thesteps of providing a base station 104 positioned in the vehicle 102 anda mobile communication unit 122, wherein the base station 104 comprisesa first transmitter for transmitting signals and a first receiver forreceiving a signal from the mobile communication unit 122 in response tosaid transmitted signal. The method includes receiving a first requestfrom the mobile communication unit 122 seeking performance of a vehiclefunction. Upon receiving the request, the base station 104 determines aposition of the mobile communication unit 122 relative to the vehicle102 and compares the position against a predetermined criteriaassociated with the requested function. If the position of the mobilecommunication unit 122 relative to the vehicle 102 satisfies therelevant criterion, the base station 104 facilitates fulfilment of therequest and performance of the requested function. As described above,multiple requests may be accommodated, each requiring satisfaction of aunique criterion or set of criteria.

As described above, the base station 104 may be configured to determinepositions of the mobile communication unit 122 relative to the vehicle102 based on a time of flight methodology. It should be appreciated,however, that other means for determining a position of the mobilecommunication unit 122 may be equally applicable.

The vehicle communication system 100 can optionally also provide keylessengine starting for the vehicle 102. By using the ranging data from thetransceivers 110, 112, 114, the electronic control unit 106 candetermine when the mobile communication unit 122 is inside the vehicle102. A control signal can be transmitted to the engine control unit, viathe CAN bus 120, to permit keyless engine starting when a Start buttonis pressed.

The vehicle communication system 100 according to the present inventioncan be further refined. In particular, the electronic control unit 106can be configured to transmit a status signal to the mobilecommunication unit 122. For example, if the base station 104 detects amis-lock scenario, the status signal may instruct the mobilecommunication unit 122 to generate a first user alert. Equally, thestatus signal may instruct the mobile communication unit 122 to generatea second user alert (which is different from the first user alert) whenthe vehicle 102 has been locked. The first and/or the second user alertcould be provided instead of, or in addition to, any notificationprovided by the vehicle 102. The mobile communication unit 122 couldcomprise an audio, optical or haptic output for indicating the vehiclestatus. For example, the mobile communication unit 122 could compriseone or more of the following: LED(s), a text screen or a vibratingmechanism.

The mobile communication unit 122 is also provided with one or morebuttons to allow a user to trigger locking/unlocking of the vehicledoors from outside of the authorization zone 138.

The ultra-wideband (UWB) transceivers 110, 112, 114, 124 describedherein are compliant with IEEE802.15.4a protocol.

The vehicle communication system 100 can monitor time of flight (ToF)communications between the base station 104 and the mobile communicationunit 122 to provide improved security, for example to protect against arelay-station security attack.

A door unlock override switch can be provided to unlock the doors142-148 in the event of an emergency.

The skilled person will understand that various changes andmodifications can be made to the vehicle communication system 100described herein without departing from the spirit and scope of thepresent invention. For example, a welcome lights function could besupported by illuminating an interior and/or exterior vehicle light whenthe mobile communication unit 122 enters the authorization zone 138.

Although the vehicle communication system 100 has been described withreference to the mobile communication unit 122 transmitting the pollingsignal, the system could also operate if the base station 104transmitted the polling signal. For example, the first transceiver 110of the base station 104 may transmit a polling signal which, whenreceived by the remote transceiver 124, initiates communication betweenthe mobile communication unit 122 and the base station 104. In oneembodiment, upon receipt of the polling signal, the mobile communicationunit responds by transmitting a response signal. The response signal isreceived by the first transceiver 110 and the electronic control unit106 validates the response signal.

The mobile communication unit 122 includes a motion sensor, such as agyroscope or an accelerometer, to detect movements of the mobilecommunication unit 122. Signals based on the detected movements may thenbe transmitted to the base station 104 for use in deciding whether, whenand how to facilitate control over functions of the vehicle 102. Forexample, if the base station 104 determines that the mobilecommunication unit 122 has been stationary for a predetermined period oftime, the base station 104 may cause the mobile communication unit 122to be disabled or to enter a sleep mode. In addition, the base station104 could transmit a disable signal to deactivate the transceivers 110,112, 114, 124. Alternatively, the transceivers 110, 112, 114, 124 couldbe disabled automatically if they do not receive an authorization signalfor a predetermined period of time. The mobile communication unit 122could be awakened by an activation signal from the motion sensor when itdetects movement.

Moreover, it will be appreciated that it is not necessary for a vehiclecommunication system 100 according to the present invention to provideall of the operating modes described herein. Rather, one or more of theoperating modes could be embodied in a vehicle communication system 100in accordance with the present invention.

It will be appreciated that various changes and modifications can bemade to the present invention without departing from the presentinvention. Further aspects of the present invention will be describedwith reference to the following numbered paragraphs.

1. A vehicle communication system (100) for facilitating control over afunction of a vehicle (102), the vehicle communication system (100)comprising: a base station (104) positioned in the vehicle (102); and amobile communication unit (122); the base station (104) comprising afirst transmitter for transmitting a signal to the mobile communicationunit and a first receiver for receiving a signal from the mobilecommunication unit (122); the base station (104) configured to: receivea first request from the mobile communication unit (122), wherein thefirst request seeks performance of a first vehicle function; determine aposition of the mobile communication unit (122) relative to the vehicle(102); compare the position of the mobile communication unit (122)relative to the vehicle (102) to a first criteria; and facilitateperformance of the first vehicle function if the position of the mobilecommunication unit (122) relative to the vehicle (102) satisfies thefirst criteria.

2. A vehicle communication system (100) as described in paragraph 1,wherein the base station (104) is configured to determine the positionof the mobile communication unit (122) relative to the vehicle (102)based on a time of flight method.

3. A vehicle communication system (100) as described in paragraph 1,wherein the base station (104) is configured to facilitate performanceof the first vehicle function only if the position of the mobilecommunication unit (122) satisfies the first criteria.

4. A vehicle communication system (100) as described in paragraph 1,wherein the first criteria requires that the position be less than afirst distance from the vehicle (102).

5. A vehicle communication system (100) as described in paragraph 1,wherein the first criteria requires that the position be greater than afirst distance from the vehicle (102).

6. A vehicle communication system (100) as described in paragraph 1,wherein the base station (104) is configured to: receive a secondrequest from the mobile communication unit (122), wherein the secondrequest seeks performance of a second vehicle function; compare theposition of the mobile communication unit (122) relative to the vehicle(102) to a second criteria; and facilitate performance of the secondvehicle function if the position of the mobile communication unit (122)relative to the vehicle (102) satisfies the second criteria

7. A vehicle communication system (100) as described in paragraph 6,wherein the base station (104) is configured to facilitate performanceof the first vehicle function only if the position of the mobilecommunication unit (122) satisfies the first criteria, and wherein andthe base station (104) is configured to facilitate performance of thesecond vehicle function only if the position of the mobile communicationunit (122) satisfies the second criteria.

8. A vehicle communication system (100) as described in paragraph 6,wherein the first criteria requires that the position be within a firstdistance from the vehicle (102), and wherein the second criteriarequires that the position be within a second distance from the vehicle(102).

9. A vehicle communication system (100) as described in paragraph 8,wherein the first distance is greater than the second distance.

10. A vehicle communication system (100) as described in paragraph 6,wherein the base station (104) is configured to: receive a third requestfrom the mobile communication unit (122), wherein the third requestseeks performance of a third vehicle function; compare the position ofthe mobile communication unit (122) relative to the vehicle (102) to athird criteria; and facilitate performance of the third vehicle functionif the position of the mobile communication unit (122) relative to thevehicle (102) satisfies the third criteria.

11. A vehicle communication system (100) as described in paragraph 10,wherein the base station (104) is configured to facilitate performanceof the first vehicle function only if the position of the mobilecommunication unit (122) satisfies the first criteria, and wherein andthe base station (104) is configured to facilitate performance of thesecond vehicle function only if the position of the mobile communicationunit (122) satisfies the second criteria, and wherein and the basestation (104) is configured to facilitate performance of the thirdvehicle function only if the position of the mobile communication unit(122) satisfies the third criteria.

12. A vehicle communication system (100) as described in paragraph 10,wherein the first criteria requires that the position be within a firstdistance from the vehicle (102), wherein the second criteria requiresthat the position be within a second distance from the vehicle (102),and wherein the third criteria requires that the position be within athird distance from the vehicle (102).

13. A vehicle communication system (100) as described in paragraph 12,wherein the first distance is greater than the second distance, andwherein the second distance is greater than the third distance.

14. A vehicle communication system (100) as described in paragraph 1,wherein the first vehicle function comprises locking an aperture of thevehicle (102).

15. A vehicle communication system (100) as described in paragraph 6,wherein the second vehicle function comprises starting an engine of thevehicle (102).

16. A vehicle communication system (100) as described in paragraph 10,wherein the third vehicle function comprises opening an aperture of thevehicle (102).

17. A vehicle communication system (100) as described in paragraph 10,wherein the third vehicle function comprises closing an aperture of thevehicle (102).

18. A method for facilitating control over a function of a vehicle (102)comprising: providing a base station (104) positioned in the vehicle(102) and a mobile communication unit (122), the base station (104)comprising a first transmitter for transmitting a signal and a firstreceiver for receiving a signal from the mobile communication unit(122); receiving a first request from the mobile communication unit(122), wherein the first request seeks performance of a first vehiclefunction; determining a position of the mobile communication unit (122)relative to the vehicle (102); comparing the position of the mobilecommunication unit (122) relative to the vehicle (102) to apredetermined first criteria; and facilitating performance of the firstrequest if the position of the mobile communication unit (122) relativeto the vehicle (102) satisfies a first criteria.

19. A method for facilitating control over a function of a vehicle (102)as described in paragraph 18, further comprising: receiving a secondrequest from the mobile communication unit (122), wherein the secondrequest seeks performance of a second vehicle function; comparing theposition of the mobile communication unit (122) relative to the vehicle(102) to a second criteria; and facilitating performance of the secondvehicle function if the position of the mobile communication unit (122)relative to the vehicle (102) satisfies the second criteria.

20. A method for facilitating control over a function of a vehicle (102)as described in paragraph 19, further comprising: receiving a thirdrequest from the mobile communication unit (122), wherein the thirdrequest seeks performance of a third vehicle function; comparing theposition of the mobile communication unit (122) relative to the vehicle(102) to a third criteria; and facilitating performance of the thirdvehicle function if the position of the mobile communication unit (122)relative to the vehicle (102) satisfies the third criteria.

21. A vehicle having a vehicle communication system, or being adapted toperform a method as described in paragraph 1 or 18.

1. A vehicle communication system for facilitating control over afunction of a vehicle, the vehicle communication system comprising: abase station positioned in the vehicle; and a mobile communication unit;the base station comprising a first transmitter for transmitting asignal to the mobile communication unit and a first receiver forreceiving a signal from the mobile communication unit; the base stationconfigured to: receive a first request from the mobile communicationunit, wherein the first request seeks performance of a first vehiclefunction; determine a position of the mobile communication unit relativeto the vehicle; compare the position of the mobile communication unitrelative to the vehicle to a first criteria; and facilitate performanceof the first vehicle function if the position of the mobilecommunication unit relative to the vehicle satisfies the first criteria,wherein the first criteria requires that the position be greater than afirst distance from the vehicle.
 2. The vehicle communication system asclaimed in claim 1, wherein the first criteria requires that the mobilecommunication unit is outside of the vehicle.
 3. The vehiclecommunication system as claimed in claim 1, wherein the base station isconfigured to: receive a second request from the mobile communicationunit, wherein the second request seeks performance of a second vehiclefunction; compare the position of the mobile communication unit relativeto the vehicle to a second criteria; and facilitate performance of thesecond vehicle function if the position of the mobile communication unitrelative to the vehicle satisfies the second criteria.
 4. The vehiclecommunication system as claimed in claim 3, wherein the base station isconfigured to facilitate performance of the first vehicle function onlyif the position of the mobile communication unit satisfies the firstcriteria, and wherein the base station is configured to facilitateperformance of the second vehicle function only if the position of themobile communication unit satisfies the second criteria.
 5. The vehiclecommunication system as claimed in claim 4, wherein the first criteriarequires that the position be greater than a first distance from thevehicle, and wherein the second criteria requires that the position bewithin a second distance from the vehicle.
 6. The vehicle communicationsystem as claimed in claim 3, wherein the first criteria requires thatthe mobile communication unit is outside the vehicle and the secondcriteria requires that the mobile communication unit is inside thevehicle.
 7. The vehicle communication system as claimed in claim 1,wherein the base station is configured to determine the position of themobile communication unit relative to the vehicle based on a time offlight method.
 8. The vehicle communication system as claimed in claim1, wherein the first transmitter is an ultra-wideband transmitter andthe first receiver is an ultra-wideband receiver.
 9. The vehiclecommunication system as claimed in claim 1, wherein the base station isconfigured to facilitate performance of the first vehicle function onlyif the position of the mobile communication unit satisfies the firstcriteria.
 10. The vehicle communication system as claimed in claim 3,wherein the base station is configured to: receive a third request fromthe mobile communication unit, wherein the third request seeksperformance of a third vehicle function; compare the position of themobile communication unit relative to the vehicle to a third criteria;and facilitate performance of the third vehicle function if the positionof the mobile communication unit relative to the vehicle satisfies thethird criteria.
 11. The vehicle communication system as claimed in claim10, wherein the base station is configured to facilitate performance ofthe first vehicle function only if the position of the mobilecommunication unit satisfies the first criteria, and wherein the basestation is configured to facilitate performance of the second vehiclefunction only if the position of the mobile communication unit satisfiesthe second criteria, and wherein the base station is configured tofacilitate performance of the third vehicle function only if theposition of the mobile communication unit satisfies the third criteria.12. The vehicle communication system as claimed in claim 1, wherein thefirst vehicle function comprises locking an aperture of the vehicle. 13.The vehicle communication system as claimed in claim 3, wherein thesecond vehicle function comprises starting an engine of the vehicle. 14.The vehicle communication system as claimed in claim 10, wherein thethird vehicle function comprises opening or closing an aperture of thevehicle.
 15. A method for facilitating control over a function of avehicle comprising: providing a base station positioned in the vehicleand a mobile communication unit, the base station comprising a firsttransmitter for transmitting a signal and a first receiver for receivinga signal from the mobile communication unit; receiving a first requestfrom the mobile communication unit, wherein the first request seeksperformance of a first vehicle function; determining a position of themobile communication unit relative to the vehicle; comparing theposition of the mobile communication unit relative to the vehicle to apredetermined first criteria; and facilitating performance of the firstrequest if the position of the mobile communication unit relative to thevehicle satisfies a first criteria, wherein the first criteria requiresthat the position be greater than a first distance from the vehicle. 16.The method as claimed in claim 15, wherein determining the position ofthe mobile communication unit relative to the vehicle is based on a timeof flight method, optionally wherein the first transmitter is anultra-wideband transmitter and the first receiver is an ultra-widebandreceiver.
 17. The method for facilitating control over a function of avehicle as claimed in claim 15, further comprising: receiving a secondrequest from the mobile communication unit, wherein the second requestseeks performance of a second vehicle function; comparing the positionof the mobile communication unit relative to the vehicle to a secondcriteria; and facilitating performance of the second vehicle function ifthe position of the mobile communication unit relative to the vehiclesatisfies the second criteria.
 18. The method for facilitating controlover a function of a vehicle as claimed in claim 17, further comprising:receiving a third request from the mobile communication unit, whereinthe third request seeks performance of a third vehicle function;comparing the position of the mobile communication unit relative to thevehicle to a third criteria; and facilitating performance of the thirdvehicle function if the position of the mobile communication unitrelative to the vehicle satisfies the third criteria.
 19. A vehiclehaving a vehicle communication system as claimed in claim
 1. 20. Avehicle being adapted to perform a method as claimed in claim 15.